xref: /linux/drivers/md/dm-audit.c (revision 702648721db590b3425c31ade294000e18808345)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Creating audit records for mapped devices.
4  *
5  * Copyright (C) 2021 Fraunhofer AISEC. All rights reserved.
6  *
7  * Authors: Michael Weiß <michael.weiss@aisec.fraunhofer.de>
8  */
9 
10 #include <linux/audit.h>
11 #include <linux/module.h>
12 #include <linux/device-mapper.h>
13 #include <linux/bio.h>
14 #include <linux/blkdev.h>
15 
16 #include "dm-audit.h"
17 #include "dm-core.h"
18 
19 static struct audit_buffer *dm_audit_log_start(int audit_type,
20 					       const char *dm_msg_prefix,
21 					       const char *op)
22 {
23 	struct audit_buffer *ab;
24 
25 	if (audit_enabled == AUDIT_OFF)
26 		return NULL;
27 
28 	ab = audit_log_start(audit_context(), GFP_KERNEL, audit_type);
29 	if (unlikely(!ab))
30 		return NULL;
31 
32 	audit_log_format(ab, "module=%s op=%s", dm_msg_prefix, op);
33 	return ab;
34 }
35 
36 void dm_audit_log_ti(int audit_type, const char *dm_msg_prefix, const char *op,
37 		     struct dm_target *ti, int result)
38 {
39 	struct audit_buffer *ab = NULL;
40 	struct mapped_device *md = dm_table_get_md(ti->table);
41 	int dev_major = dm_disk(md)->major;
42 	int dev_minor = dm_disk(md)->first_minor;
43 
44 	switch (audit_type) {
45 	case AUDIT_DM_CTRL:
46 		ab = dm_audit_log_start(audit_type, dm_msg_prefix, op);
47 		if (unlikely(!ab))
48 			return;
49 		audit_log_task_info(ab);
50 		audit_log_format(ab, " dev=%d:%d error_msg='%s'", dev_major,
51 				 dev_minor, !result ? ti->error : "success");
52 		break;
53 	case AUDIT_DM_EVENT:
54 		ab = dm_audit_log_start(audit_type, dm_msg_prefix, op);
55 		if (unlikely(!ab))
56 			return;
57 		audit_log_format(ab, " dev=%d:%d sector=?", dev_major,
58 				 dev_minor);
59 		break;
60 	default: /* unintended use */
61 		return;
62 	}
63 
64 	audit_log_format(ab, " res=%d", result);
65 	audit_log_end(ab);
66 }
67 EXPORT_SYMBOL_GPL(dm_audit_log_ti);
68 
69 void dm_audit_log_bio(const char *dm_msg_prefix, const char *op,
70 		      struct bio *bio, sector_t sector, int result)
71 {
72 	struct audit_buffer *ab;
73 	int dev_major = MAJOR(bio->bi_bdev->bd_dev);
74 	int dev_minor = MINOR(bio->bi_bdev->bd_dev);
75 
76 	ab = dm_audit_log_start(AUDIT_DM_EVENT, dm_msg_prefix, op);
77 	if (unlikely(!ab))
78 		return;
79 
80 	audit_log_format(ab, " dev=%d:%d sector=%llu res=%d",
81 			 dev_major, dev_minor, sector, result);
82 	audit_log_end(ab);
83 }
84 EXPORT_SYMBOL_GPL(dm_audit_log_bio);
85